Apparatus for cutting stone.



No. 633,974. Patented Sept. 26, I899.

' F. M. llcLABTY.

APPARATUS run cumns STONE.

(Applicatio n filed an. 6, 1899.) (I'lo Modal.) 3 Sheets8heet Tu: nouns mews cm. mm-ufl-n. wnumwou, u. c.

- PatentadlSoptfiZG, 1399. F. M. HOLABTY. APPARATUSVFOB CUTTINQ STONE.

(Appliution m In. s, 1899.;

(lo mm.)

3 Shanta-Sheet 2,

- 2c. THE "cams versus 0.. Puormrmn. w .sm-mnu u N0. 633,974. Patented Sept. 26, I399.

. F. m. MBJLARTY.

APPARATUS FUR CUTTING STONE.

(Application filed Jim 6, 1899.) {No Model.) 7 3 Sheets-Sheet 3.

e1 i E UNITED STATES PATENT OFFICE.

FAR UHAR M. MCLARTY, or GREENOCK, SCOTLAND.

'APPARATU'S FOR our'rmc STON E.

SPECIFICATION forming part of Letters Patent No. 633,974, dated September 26, 1899,

Application filed u ryti, 1899. Serial No. 701,886. on modelfi:

To all wlwnt it may concern;

Be it known that 1, FARQUHAR MATHESON MOLARTY, mechanical engineer, a subject of the Queen of Great Britain and Ireland, and a resident of 52 Forsyth street, Greenock, in the cou nty ofrRenfrew, Scotland, have invented certain new and useful Improvements in and Apparatus for Cutting Stone or Like Materials, (for which Iv have applied'for a patent in Great Britain, No. 4,328, dated February 21, 1893,) of which the following is a specification. r

The object of my invention is to effect the cutting of stone or like materials that is to say, materials which have a small degree of elasticity and whose. tensile strength is mate rially less than their crushing strengthin circular, straight, or other lines in a manner that will overcome many of the difficulties which have hitherto been experienced in connection with the execution of such work. In the case, say, of jumping a hole in rock by the ordinary methods the tools or jumpers are subjected to shock of such violence that they frequently break. They are, moreover, subjected to uneven wear, because the outer edges of the chisel or jumper have more work to do than have the edges nearer to the center, so that the tool or jumper rapidiybecomes useless and frequent renewals are necessary, while there is also a lessening of the diameter of the hole, owing to the extra wear on the outer edges of the tools or jumpers, so that when a hole of a given diameter is required it is necessary, especially in boring holes of considerable depth, to begin with a larger hole than is required, so as to be able to finish at the desired diameter. 1

Accordingto my invention 1 provide means for separating any desired part of the stone or the like (I will hereinafter refer t0 it as stone for the sake of sirn plicity) whether it be in portable pieces or in place as fixed rock, so that the stone is attacked in the direction in which its power of cohesion is most vulnerable without subjecting the tools to injurious shock, such as that hereinbefore referred to in the case of jumpers, and in a manner which reduces the Wear of such tools hitherto experienced in this class of work, while my method of applyingthe force necessary for separation is such that a comparatively small amount'of power suffices for'borin g large holes and for cutting up large blocks of stone into pieces suitable for building or other purposes in which the stone is required to be of specific form and dimensions.

Although according to my invention the main principles hereinbefore explained govern the work of separation and the applica- =tion of the force, the detailsby which these principles, according to my invention, are applied can be varied, as can also the methods of removing the debris; but I will describe some applicationsof the invention in order to make clear the nature thereof and the manner in which it can'be performed.

The separating-tools, according to my in vention, consist of circular toothed cutters capable of rotating on their centers While being traversed in a circle or in a straight or in other line, as required, the said teeth bearing on the stone and theload or force bearing on the cutters very much as the load on a cart is borne on the wheels thereof, so that the efiect is that when a load is applied and traversing motion is given to the cutters the teeth sink into the stone one after another and break it bit by bit. The slicing efiect being practically on a line'with the direction of the load or equivalent force, it follows that in the case of a vertical bore the action of the teeth is to slice downward, separating the bits to the rearward of them, one side of each of which has'by the action of the cutter been out or wedged away, so that the part attacked is easily separated. In the case of a borehole'a set or sets of such cutters is or are used, (one set extending from the center to the circumference,) preferably not less than one set on two opposite sides of the center, each too h in turn doing its share of the work, to be im ediately followed by the next, and so on, one of the advantages being that each cutter has a multiplicity of cutting or wedging edges, and from that cause alone there is (in comparison to the methods hitherto used for boring) greatly-increased durability. A small or a great number of'lines of such cutters can be used, the effect described not being limited excepting by the room there may be to work in. Besides the durability obtained from the aforesaid features, there is the further lessening of wear from the attacking of the stone in the direct-ion of least resistance to separation.

In the case of boring a hole the diameter of each cutter can be made so that its circumference and the circumference of the line around which it cuts differ, so that each tooth continuously changes its point of attack, the object being to secure the easy removal of the ridges which the action of the cutter would be apt to leave if the teeth were allowed to come at each rotation onto exactly the same point which had been previously attacked thereby. This change can be effected also by making the teeth of the cutters traveling in the same line of uneven pitch, and in short the arrangement can be such that every particle of the stone can bein turn attacked with any desired force without injurious shock and with any desired size of cut.

The power required for working cutters according to my invention is small in comparison to the power requred for working according to the methods hitherto in use, not

only because of the reduction of the resistance to separation, but also because any loaded machine resting on wheels bearing on a hard surface can be moved by a force representing only asmall fraction of the load.

A set of cutters for boring will preferably (though not necessarily) be of varying diameters. They preferably vary in diameter because the farther the operative part of each cutter is from the center the longer will be the line on which it rotates. Hence in order to give each tooth a more nearly equal amount of work to do the outer cutters should be larger in diameter than those nearer to the center in proportion to the relative length of the path on which they act.

Of the various means of clearing away the grit from the cutters-namely, fluids under pressure, brushes, scrapers, elevators, or the likethe use of water under pressure is preferred, as it when directed onto the cutters clears them instantly and has the advantage of keeping the cutters free in action, so that wear on the cutters from the grit being pressed between them and the stone being cut is prevented, the separating effect being obtained from the direct action of the cutters themselves in the manner described.

In cutting in other than circular lines the teeth may be made to act by either backward or forward action, or by both, as may be desirable, according to the nature of the work to be done, and in cutting in a circular direction the teeth, can be made to cut in either direction 01', more especially, in one direction, as may be desired.

The great utility of my invention in cutting large blocks of stone into pieces suitable for building or other purposes in which stone is required to be of specific form and dimensions will be understood by comparison with the methods hitherto used in such work. The methods of cutting hitherto used are such that the tools besides having to overcome the adhesion of the particles to their immediate neighbors have to overcome the much greater resistance offered by the material forward of the point of attack, whereas according to my invention the only resistance to separationis that due to the adhesion of the particles to their i m mediate neighbors, which is extremely small as compared to the crushing strength of stone, which crushing strength is opposed to the cutting action in the methods hitherto in use.

What I have stated regarding the characteristics of my invention in relation to boring holes applies also to cutting blocks of stone in straight or other lines. For instance, in dividing a block of stone into straight slabs the only difference is that the cutters travel in straight lines, whereas in hole-boring they travel in circles.

In all cases there are the following simultaneous movements of the cuttersnamely, the movement by which the cutters are carried in the desired direction-as, for instance, in the direction of the arrow or in the diagram Figure 1 of the accompanying drawings, the rotary movement of the cutters beingin the direction of the arrow y, by which (in conjunction with the first-named movement) a new point of contact is obtained, and the move ment of each tooth at the moment of contact, which latter movement is obtained by acombination of the first-named movements with the movement of the feed of the cutters in the direction of the arrow 5. In the said diagram, 1; represents the part of the stone which has been operated upon, and n: represents the part which is to be operated upon. The result of the several movements is a thrusting action of each tooth nearly at right angles to the line in which the axis of the cutter is traveling, so that the separating effect of each tooth may be likened to the action of a wedge or tapered chisel when it is driven into stone at a point in close proximity to the edge thereof, the corresponding edge u in the diagram, according to my invention, being formed by the preceding tooth, and as the teeth follow each other the stone is separated by breaking it bit by bit. By these means the separation can be effected with such a degree of nicety that a practically even and smooth surface can be produced, while by suitably pitching and angling the teeth and increasing the ratio of feed even and rough surfaces can be produced, as desired.

The foregoing explains the principles of my invention, and in order that its practical application may be clearly understood I will refer to the accompanying drawings, in which are illustrated by way of example methods of applying the cutters to machines whose motions fit them to bore, divide, plane, or mold,

as required.

Figs. 1 and 2 show in elevations at right angles to each other a cutter in its holder, with part of the blade on which the holder is mounted, for dividing stone to the depth A. Fig. 3 shows in elevation a seriesof such cutters in their holders and the edge view of the blades on which the holders are mounted 1 and also. part of the tool-bar to which the said blades are secured and means for securing the blades to the tool-bar, so that they can be adjusted, the cutters being shown as cutting straight edges on a corresponding number of slabs of stone. Figs. 4 and 5 show in elevations at right angles to each other double andsingie cutters,,holders,and blades, and part of the tool-bar, with means for adjusting and fixing the blades, thearrangement being suited for dividing stone to any depth allowed by the blades by the action of small cutters, which entirely enter the stone operated on, clearing the way for the blades and which produce two plane surfaces in each division. Figs. (3 and 7 show, on a larger scale than that of Figs. 4 and 5, a double cutter-holder therefor and part of a blade, the figures b'eing'elevations at right angles to each other. Figs. 8 and 9 show a single cutter with its holder and part of a blade, the figures being also elevations at right angles to each other. Fig. 10 shows in elevation three molding-cutters with their holders and blades and part of the tool-bar, the said outters being raised out of contact after having molded the edges of six blocks of stone. Fig. 11 shows six cutters, with their holders' and blades and part of the tool-bar, in the act of.

producing'a plane surface, or, if desired, a series of plane surfaces or steps, on a block of stone. Figs. 12 and 13 show in elevation and sectional plan, respectively, a set ofcutters arranged for boring holes. 111 all the figures corresponding parts are marked with the same letters ofreference.

For dividing blocks of stone and at the same time producing even faces thereon and also for molding the edges of stone or for producing a plane surface or plane surfaces on an outside face of a block of stone the apparatus consists principally of the cutters ct i, holders a therefor, adjustable blades a, for carrying the cutter-holders, means of fixing the blades .at any desired position within the scope of the tool-bar, and the tool-bar B, which is made so as to be attachable to and controllable by a holder in any machine havinga recipfeeding in the direction in which boring is to.

be done.

"The cutters may for some kinds of material be of ordinary malleable iron or the like, but they are preferably of tool-steel tempered to suit the kind of work for which they are intended. Their axis may be in any position suitable to the work required of the cutters;

but preferably the axis is in a shank which can be rapidly placed and secured in a socket attached to a tool-bar, the object being to afford a means of quickly changing the tools for instance, when it is required to substitute a set of molding-cutters for a set of dividing-cutters, so that immediately blocks of stone have been divided they can be molded without any waste of time.- The axes of the cutters may travel outside of the material being cut, when they may be mounted, as shown in Figs. 1, 2, 3, 10, and 11, or they may travel within it by their holders being let flush into stiff blades, the one end of which is firmly attached to the tool-bar, the cutters carried by the other end'of each blade being so proportioned or arranged as to give a Width of cut sufficient for the entrance of the blades, as illustrated in Figs. 4 to 9. I

The cutters may be small orlarge in diameter, and they may be thick or thin, and the teeth of the respective cutters may be situated at the same distances from their centers or at unequal distances in the diderent cutters, so as to cut a molding of any desired form when the cutters are run to and fro across a stone and fed thereinto. may vary with their pitch and depth and with the diameter of each particular cutter and with the particularpurposefor which they areintended. In the case of teeth intended to separate on the backward stroke as Well as on the forward stroke the portions of each tooth on either side of a line drawn from the point of the tooth will be symmetrical-that is to say, the angle on each side ofthe center line of each tooth will be the same. These angles may differ in different cutters according to the degree of wedging efiect desired. When, however, action of the cutters on the stone is required only during the stroke in one direction, one of the sides of each toot-h may be angled, so as to bemore free from contact than the sideof tooth used as a wedge.

The cutters may be formed by punching, pressing, stamping, or casting to required shape or by milling; but for most purposes in stone-cutting thin sheets of steel punched cold and grouped together will be found preferable on account of the rapidity with which they can be made in apoWer-pre'ss and on account of the small amount of steel required for a set of cutters of small diameter, such as are preferred for most purposes, and because small cutters, such as are illustrated in Figs. 4 to 9 and in Fig. 11, can be readily and rapidly dressed by means of an ordinary saw-file, so that their efficiency can be maintained cheaply and readily and without the aid of costly tools. XVith holders secured to the blades as illustrated the tools can be quickly removed and replaced, so that no time need be lost in changing the cutters, and when the small cutters are worn out the quantity of steel lost is inconsiderable. The small-sized cutters attached to blades, as illustrated in Figs. 4: to 9, are specially adapted for divid The angles of the teeth 4 action.

ing deep blocks of stone and arcalso suitable when properly placed for producing plane surfaces on blocks of stone. For dividing the cutters may be in any desired number which each blade will accommodate, they being carried one behind the other along the lower edge of the blade, as shown in Fig. 5, and every alternatecutter is double, the journal being between the pair, as shown in Figs. 6 and 7, the intervening cutters being single, as shown in Figs. 8 and 9, the holder taking the strain on each side of the cutter. The double cutters act on thestone at parts which are not touched by the single cutter and the single cutters out what thedouble cutter does not touch, the object of the device being to clear the way for theblades to which thecutter-holders are secured. This is effected by the double cutter, because its outer sides extend beyond the sides of blades, as seenin Fig. 6; but the double cutters alonecould not-complete the work owing to the space required for what may be termed the fulcrum, so that the single cutters are required to cut away what the double cutters leave. To insure a complete clearance,the outer edges of, the single cutters should extend beyond the. inner edgesof, the doublewcutters, the outer sides of which are preferably slightly concave, so that the cutter edges are farther out. than themiddle of the cutter-disks. By this means cutters of very small diameter canbe used for dividing deep stone and the like, though of course cutters of any desired diameter can be used. For dividing cutters may be used of such a diameter thatthe 'ful-' crum will never enterthe divided space, and in such casesone cutter (which may be a thin one) may be used for each dividing out, though if the dividing out be very deep it will, generally speaking, be found more economical to use the arrangement of small cutters hereinbefore described. In the case, however, of cutting the edges of, say, paving-stones thin cutters will be preferable. I11 that case the stones may be laid one above another, with the edge of each stone back from the edge of the one immediately under it, so that the projecting parts represent a series of steps. (See Fig. 3.) Then by setting, by means of the screwed rods 1) and nuts 0, theblades at the properdistances apart to act oneach stone, the blades being of varying lengths to suit the positions of the several stones, the whole of the edges canbe cut simultaneously by the said cutters.

, Pieces of wood 6 should be placed beneath the stones, as shown, to support them and also to keep them at such a distance from each other that the cutters will not touch the stones which are below those which they have cut.

In molding the cutters run in journals on either side, as illustrated in Fig. 10.

In producing plane surfaces on the outer sides of stone the cutters may run in rows similarly to the arrangements explained for dividing operations.

is such that the blades can be spaced as required and the sides of the bladesbe adjusted vertically and on a line with the intendedline of cut with great accuracy. There are flanges cl secured to the blades, which have set-pins for fixing them in the adjusted position, and above there are adjustable bars 6. These arrangements retainthe blades firmly in the positions proper for each operation, the blades being made sufficiently rigid to be free from flexure. In the case of separating stone, as illustrated in Fig. 3, where the cutters enter-the stone to an extent less than half-their diameter, each cutter a is preferably a single disk of thin sheet-steel, because thin sheetsteel can be made sufficiently rigid to 'perform the work required ofcutters for such work; but where stone is required tobe divided for a considerable depth itis preferable to use cutters of small diameter, asillustrated in Figs. 4.-, 5,6, 7, 8, and 9, and of suchthickness (either by grouping thin disks or in single disks) as Will allow of the double cutters clearing the way for the blade'and allow the single cutter to separate the part untouched by the double cutters. ,The thickness and shape of the molding-cutters, Fig. 10, are determined by the span and shape of the. de-

sired molding and may consist of a number of thin disks of different diameters or the said cutters when if the same diameter of theparts which are of the same diameter may be each in one piece, while the diameters of the moldin g-cutters may be as small as will. allow clearance for the. cutter-holder. The latter remark applies also to cutters for.v producing planesurfaces on the face of a block of stone, as illustrated by Fig. 11; but in that casethe thickness of each cutter and the relative difference in the diameters of its component parts are dependent on the kind of work desired. In this case also the cutters mayeach consist of a number of thin disks grouped togetheror they may be in single pieces.

\Vhen cutters are made of grouped disks and of form to operate as in Figs. 10, 11, 12, and 13, each disk rotates independently of the others.

When even and smooth surfaces are desired, the pitch of teeth should be fine and the cutters should be finely fed to their work, while the speed at which the cutters can be actuated is limited only by the speed of the machine used to work them, because the cutters when operating according to my invention will not become unduly heated.

The advantages ofthe method of ope ration according to myinvention will be clearly understood when it is consideredthat-by lightly striking a suitable chisel pieces can be separated from the edges of a block of stone and that by lightlystriking wedges large blocks of sandstone can be split, so that vast numbers of particles can be separated with small effort in a very short time, and when it is remembered that the latter easy and rapid hand operation (in a direction similar to that of separation according to my invention) is separation en masse, while I separate in detail, it becomes evident that the resistance in operating according to my invention is extremely smalL. It is for that reason that the cutters according to my invention when working at a very great speed have small liability to heat, and for the same reason the power absorbed by the resistance to separation is very small; but these hand-worked methods of separation resemble separation according to my invention only in respect to similarity in the smallness of resistance, for in all other respects the respective results are entirely different. Besides bruising the edges of the stone and oftenbreaking it in a different manner from that intended, the new surfaces obtained by splitting sandstone, for example, are in all cases so irregular that the stone has afterward to be dressed before it can be said to be finished, whereas according to my invention the act of separation also finishes the stone, giving it an even and smooth surface or an even and rough surface, as may be desired, while in no case is there any liability to break any more of the stone than the particles in close proximity to. each tooth at the moment of its action on the material.

As before stated, the cutters can be operated by any planing, boring, or analogous machine, provided that when the cutters are in contact with the stone to be operated upon and the driving motion is applied the said cutters will rotate truly on their axes and.

- declare that what I claim is apex of each tooth extending across the peripheryof the cutter, and the side or sides of said teeth being inclined in a longitudinal direction; means for applying thereto a force to cause the said teeth to enter the material, and means for imparting a traversing movement to the said cutter or cutters such that when the apparatus is in operation the said teeth successively enter the material forward of each other and breakoff successive portions in a rearward direction, substantially as described.

2. Means for cutting stone or the like consisting of the combination of a circular cutter wheel or disk having a series of wedgelike teeth extending entirely around the periphery thereof, the line of the apex of each tooth extending across the peripheral edge of the wheel, and the inclined side or sides of said teeth being flat or straight both in'a lateral and longitudinal direction, a carrier or carriage, an axle or pivot on the carrier on which the cutter-wheel is free to rotate, means for applying to the carriage a force to cause the teeth of the cutter to enter the material, and means for imparting a traversing movement to the carriage while maintaining the pressure, thereby causing the said wedge-like teeth to enter the material forward of each other and breakoif the successive portions in a rearward direction, substantially as described.

3. Means for cutting stone or the like consisting of the combination of a series of circular cutter wheels or disks, each having a se ries of wedge-like teeth extending entirely around the periphery thereof, the line of the apex of each tooth extending across the peripheral edge of they wheel, and the inclined side or sides of said teeth being flat orstraight both in a lateral and longitudinal direction, a carrier or carriage on which the cutterwheels are mounted side by side and are free to rotate, means for applying to the carriage aforce to cause the teeth of the cutters to enter the material forward of each other and break off the successive portions in a rearward direction, substantially as described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

F. M. MCLARTY.

lVitnesses: l

. ANDREW" ROWAND FOWLER,

N IL SPROUL. 

